Reconstitution of lyophilized (freeze dried) material is often difficult to do accurately and safely. If the amount or quality of the reconstituting liquid is questionable, then the concentration or efficacy, respectively, of the reconstitution is likely to be unsatisfactory. As an example, milk products are notorious for mishandling during reconstitution in third world countries, due either to inaccuracies in the amount of liquid used or to contaminants being present. Thus, when pharmaceuticals or food products are being reconstitituted, it has been the practice to require the use of carefully trained personnel. The same has been true in other uses of lyophilized material, such as calibrators and controls.
Therefore, there has been a need, prior to this invention, to develop packaging of lyophilized material that will allow reconstitution to occur safely and accurately, without the use of skilled personnel. Such development has been hindered by the known fact that elastomeric stoppers usually used to seal a bottle of lyophilized material, are susceptible to degradation if stored in contact with the liquid that is to eventually reconstitute the dried material. Yet another problem with such stoppers has been that a mere friction-fit of the stopper in a bottle usually does not provide an adequate seal to keep lyophilized material and liquid separated. Additional crimping has been needed. Most lyophilates do not store well if they become wetted, because they deteriorate when stored in this condition.
Thus, considerable problems have occurred prior to this invention when elastomeric stoppers were used in lyophilate packaging. This has been unfortunate, since the elastomeric stoppers have the advantage of being relatively inexpensive, compared to other barriers that can be used.
Some attempts have been made heretofore to provide lyophilate packaging, particularly that which avoids the use of elastomeric stoppers. Examples are described in U.S. Pat. Nos. 3,924,741 and 4,203,517. However, regarding the container of the '741 patent, the pieces involved require complex shaping and molding that render the device quite expensive. Furthermore, the construction of plunger 11 in that container renders it difficult to lyophilize the material while it is in the plunger, so that it must be lyophilized elsewhere. Transfer of the lyophilized powder to the plunger as a separate step is too complicated to do under dry, evacuated conditions, the absence of which risk contaminating the lyophilate with moisture or bacteria. Regarding the package of the '517 patent, the non elastomeric stopper 29 that is used becomes a loose part within the reconstituted liquid, an undesirable feature during pour-off. Thus, these previous attempts tend to either sacrifice the integrity of the lyophilate, or create problems during pour-off of the reconstituted liquid.